Clamp locking mechanism in device for welding plastic tubes

Abstract

A device for welding plastic tubes includes a laterally movable tube holder having tube holding areas and a laterally fixed tube holder having tube holding areas. Each tube holder includes clamping structure for clamping each tube placed in the respective tube holder areas and for creating a fluid free area. A spring mechanism urges the laterally movable tube holder toward the laterally fixed tube holder to maintain the clamp faces flush against each other. A clamp locking mechanism is provided to supplement the action of the spring mechanism by maintaining the clamp faces flush against each other during the loading of the tubes.

1. In a device for welding plastic tubes comprising a first tube holder having first and second parallel tube holding areas, a second tube holder having first and second parallel tube holding areas which are alignable with said tube holding areas of said first tube holder whereby a first tube may be placed in the aligned first tube holding areas and a second tube may be placed in the aligned second tube holding areas, said first tube holder having a tube clamp for clamping each of the tubes in the respective tube holding areas, said second tube holder having a tube clamp for clamping each of the tubes in the respective tube holding areas whereby a fluid free area is created in each tube when said tube holders are in a loading station, one of said tube holders being laterally fixed and the other tube holder being laterally movable with respect to said fixed tube holder, and a spring mechanism urging said laterally movable tube holder toward said fixed tube holder while in said loading station, the improvement being in a clamp locking mechanism in said loading station to provide an action which supplements said spring mechanism to maintain said movable tube holder urged toward said fixed tube holder,
 wherein said clamp locking mechanism includes a pivot arm having a tip selectively imparting a force against said movable tube holder whereby said locking mechanism is in said locked position when said pivot arm tip imparts a force against said movable tube holder and said locking mechanism is in said unlocked position when said tip of said pivot arm does not impart a force against said movable tube holder, and a handle for selectively controlling the position of said tip. 
 
     
     
       2. The device of  claim 1  wherein said clamp locking mechanism is manually movable to and from a locking position and an unlocking position. 
     
     
       3. The device of  claim 1  wherein said pivot arm includes a cam profile having a locking location and an unlocking location, a lever arm mounted against said cam profile to dispose said tip selectively into said locking position and said unlocking position, and said lever arm being mounted to said handle whereby said handle controls the position of said lever arm. 
     
     
       4. The device of  claim 3  including a spring member biased against said pivot arm to urge said pivot arm to said unlocking position. 
     
     
       5. The device of  claim 4  including a guide block, and said pivot arm being mounted to a top surface of said guide block. 
     
     
       6. The device of  claim 5  wherein said lever arm is mounted on one end of a shaft, said shaft being rotatably mounted to said guide block, and said handle being mounted to an opposite end of said shaft. 
     
     
       7. The device of  claim 6  including a support bracket mounted to a side surface of said guide block, said support bracket having a recess, and said lever arm being mounted in said recess to be between said support bracket and said guide block whereby said recess confines and limits the movement of said lever arm. 
     
     
       8. The device of  claim 7  including a sensor pin mounted on said lever arm, a sensor mounted to said support bracket to sense the location of said sensor pin, and said sensor thereby giving an indication of when said lever arm is disposed in said locking position and when said lever arm is disposed in said unlocking position. 
     
     
       9. The device of  claim 8  wherein said sensor is an optical sensor, and said spring member being a leaf spring. 
     
     
       10. The device of  claim 9  including cam structure for controlling the lateral position of said movable tube holder, said cam structure having a cam shaft, and said pivot arm tip imparting a force pushing against said movable tube holder by pushing against said cam shaft. 
     
     
       11. The device of  claim 1  wherein said device has a stripping station in which said movable tube holder is laterally shifted away from said fixed tube holder. 
     
     
       12. The device of  claim 1  wherein said clamp locking mechanism includes a pivot arm having a tip selectively imparting a force against said movable tube holder whereby said locking mechanism is in said locked position when said pivot arm tip imparts a force against said movable tube holder and said locking mechanism is in said unlocked position when said tip of said pivot arm does not impart a force against said moveable table holder,
 wherein said pivot arm includes a cam profile having a locking location and an unlocking location, and a lever arm mounted against said cam profile to dispose said tip selectively into said locking position and said unlocking position. 
 
     
     
       13. The device of  claim 12  including a spring member biased against said pivot arm to urge said pivot arm to said unlocking position. 
     
     
       14. The device of  claim 13  including a guide block, and said pivot arm being mounted to a top surface of said guide block. 
     
     
       15. The device of  claim 14  including a support bracket mounted to a side surface of said guide block, said support bracket having a recess, and said lever arm being mounted in said recess to be between said support bracket and said guide block whereby said recess confines and limits the movement of said lever arm. 
     
     
       16. The device of  claim 15  including a sensor pin mounted on said lever arm, a sensor mounted to said support bracket to sense the location of said sensor pin, and said sensor thereby giving an indication of when said lever arm is disposed in said locking position and when said lever arm is disposed in said unlocking position. 
     
     
       17. The device of  claim 16  wherein said sensor is an optical sensor, and said spring member being a leaf spring. 
     
     
       18. The device of  claim 17  including cam structure for controlling the lateral position of said movable tube holder, said cam structure having a cam shaft, and said pivot arm tip imparting a force pushing against said movable tube holder by pushing against said cam shaft. 
     
     
       19. An apparatus for welding plastic tubes comprising:
 a first tube holder having first and second parallel tube holding areas; 
 a first tube clamp for clamping the tubes in the respective tube holding areas; 
 a second tube holder having first and second parallel tube holding areas, 
 a second tube clamp for clamping the tubes in the respective tube holding areas;
 wherein the second parallel tube holding areas are alignable with the first tube holder holding areas; 
 
 the first tube holders being laterally fixed and the second tube holder being laterally movable, 
 a spring mechanism; 
 a clamp locking mechanism comprising a pivot arm having a tip to maintain the second tube holder in position with respect to the first tube holder, and 
 a handle for selectively controlling the position of said tip
 wherein the clamp locking mechanism selectively imparts a force against the second tube holder; and 
 wherein the clamp locking mechanism is in a locked position when the pivot arm tip imparts a force against the second movable tube holder and the locking mechanism is in an unlocked position when the pivot arm tip is not imparting the force against the second tube holder.